Average annual temperature is 8.2 °C
Absolute maximum temperature: 37.2 °C
Absolute minimum temperature: -28.6 °C
Number of sunny days: 220 days
Number of rainy days: 100 days
Number of snow days: 45 days
Look at detailed online map of Dewey County
* Weather data for Dewey County United States is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 3.8 | 10.3 | 7.3 | 26.5 | 28.9 | 34.1 | 37.2 | 32.7 | 34.7 | 28.5 | 14.1 | 12.9 |
| Average daytime temperature (°C) | -2.7 | 1.0 | -0.8 | 10.1 | 22.8 | 27.5 | 28.9 | 27.7 | 24.2 | 13.3 | 7.4 | 3.2 |
| Average temperature (°C) | -6.6 | -5.0 | -6.0 | 3.8 | 16.6 | 21.9 | 22.7 | 22.0 | 18.3 | 8.3 | 2.4 | -1.0 |
| Average night temperature (°C) | -9.7 | -9.4 | -9.7 | -1.1 | 11.0 | 16.7 | 17.1 | 17.1 | 13.6 | 4.4 | -1.4 | -4.4 |
| Absolute minimum temperature (°C) | -24.3 | -28.6 | -19.9 | -14.9 | -0.7 | 11.4 | 10.0 | 12.6 | 8.7 | -10.9 | -11.3 | -12.6 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 15.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.2 | 10.4 | 11.9 | 13.5 | 14.9 | 15.6 | 15.2 | 14.0 | 12.5 | 11.0 | 9.6 | 8.8 |
| Daylight minimum duration (h) | 8.0 | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 8.0 |
| Sunshine mean duration (h) | 4.3 | 8.0 | 7.5 | 9.3 | 11.9 | 11.9 | 13.1 | 11.4 | 10.0 | 7.8 | 7.9 | 5.5 |
| Precipitation (mm) | 11 | 20 | 36 | 34 | 104 | 92 | 51 | 121 | 63 | 36 | 5 | 47 |
| Sunny days | 21 | 18 | 14 | 17 | 14 | 14 | 14 | 20 | 22 | 20 | 22 | 24 |
| Rainy days | 2 | 1 | 1 | 8 | 17 | 16 | 17 | 11 | 8 | 10 | 6 | 3 |
| Snow days | 8 | 9 | 16 | 5 | 0 | 0 | 0 | 0 | 0 | 1 | 2 | 4 |
The best time to visit Dewey County during the most sunny months:
Months with the longest average daylight duration in Dewey County:
The largest precipitation sum in Dewey County is at